Anti-friction bearing structure for movable sash



Nov. 17, 1959. 2,913,079

ANTI-FRICTION BEARING STRUCTURE RoR Mex/ABLE sAsH l D. E. Axl-z Filed Feb. 10, 1958l INVENT OR.

DANIEL E AXE vKGnwL- ATTORN EY A N'I'I-FRICTION BEARING STRUCTURE FOR MOVABLE SASH Daniel E. Axe, Fayetteville, N.Y., assignor to The O. M.

Edwards Company, Inc., Syracuse, N.Y., a corporation of New York Application February 1 0, 1958, Serial No. 714,115 6 Claims. (Cl. 189-72) This invention relates generally to weatherstrip construction for window assemblies having movable sash panels, and has particular reference to improved antifriction bearing structure for use in connection with pile fabric weatherstripping when the latter is interposed between the coacting metal channels and ribs that guide the sash during movement.

In window assemblies having metal framed movable sash, and particularly when such assemblies are mounted in busses, trains and the like, the window frame and sash frame are usually formed with coacting guide structure including interengaging channels and ribs to guide the sash during movement. Since it is impractical to attempt to obtain a close metal to metal fit that will be weather tight and at the same time permit the sash to slide without binding, a clearance space is left between the ribs and channels and this space is occupied by weatherstripping material which provides the necessary weather seal and also prevents the sash from rattling in the frame.

For this purpose, a fabric weatherstripping material formed with a heavy nap or pile has proved to be the most practical, and it is usually specified for use on commercial passenger carrying vehicles.

Unfortunately, however, it has been found that if the pile on the weatherstripping occupies all of the clearance space between the frame and sash so that it provides a good seal, the sash is difficult to move since the pile offers considerable frictional resistance to the movement and tends to bind the metal guide structure of the sash. If, on the other hand, only a portion of the clearance space is occupied by the pile so that the sash moves more easily, the weather seal is not as effective and the bearing surface is reduced makingt he sash subject to lateral play and cooking. This problem is complicated by the fact that in modern bus structures and the like very large sliding sash are often used, some of the window openings in such structures being as much as 72 inches across. It will be apparent, therefore, that in attempting to move a sash of such size, considerable force is necessary to overcome the frictional resistance encountered.

An acceptable solution to the problem outlined above is disclosed in Edwards et al. Patent No. 2,790,214, issued April 30, 1957, said patent and the present application being commonly owned. The Edwards patent provides for a plurality of nylon bearing strips located in the bottom of each weatherstripped guide channel, which bearing strips provide anti-friction bearing surfaces for the bottom of the metal guide structure received in the channel. This arrangement is in use at the present time on a great many commercial passenger carrying vehicles and has enabled large sized sash to be employed in these Vehicles with satisfactory results. The nylon bearing strip arrangement has a disadvantage from the manufacturers standpoint, however, in that each strip must be inserted in holes formed in the channel bottoms and then taped or otherwise secured in position, and these assembling nited States Patent() "ice,

operations have proved to be time consuming and expensive.

In order to solve the assembling problem noted above and also to gain certain additional advantages to be described hereinafter, the present invention contemplates and has as its primary object the provision of an improved anti-friction bearing structure of the character described, which structure may be quickly and easily assembled in weatherstripped' guide channels and also is constructed so that it .provides an anti-friction bearing for the sides as well as the bottom of the guide ribs received in the channesl. Briefly stated, this structure is comprised of a plurality of channel shaped bearing elements, preferably of nylon, which are simply pressed into position in the Weatherstripping, the elements having self-contained holding means to maintain them in position as will be described.

Another important object of the invention is to provide an improved anti-friction bearing structure of the character. described which allows the weatherstripping to perform its basic weather proofing function in a completely effective manner and yet reduces the binding effect of.

therweatherstripping to a minimum so that the sash will move freely. f

A further important object of the invention is to provide an improved anti-friction bearing structure of thev character described wherein the channel shaped bearing elements serve to center the guide ribs in the guide channels and thereby minimize the possibility of uneven wear on the weatherstripping pile fabric.

A still further important object of the invention is to provide an improved anti-friction bearing structure of the character described wherein the bearing elements employed are very economical to manufacture and install,

the elements being adapted for easy installation in window assemblies that are already in service as well as in new constructions.

A more specific object ofthe invention is toprovidek an improved anti-friction bearing structure wherein the channel shaped bearing elements are formed with projecting holding ribs and sharp, ilared ends that become embedded in the pile fabric of the Weatherstripping, this 'construction providing a self-contained ancho-ring or holding means to maintain the elements in fixed position in the guide channels and prevent movement relative thereto.

Another specific object of the invention is to provide anI improved anti-friction bearing structure in which the channel shaped bearing elements are constructed with slightly outwardly inclined sides to compensate for minor structural variations vand also to increase the holdingv power of the self-contained anchoring means. v Other objects and advantages of the invention will be- Figure 2 is aside elevation of one of the channelv shaped anti-friction bearing elements; Y

Figure 3 is an end elevation of the bearing element of Figure 2;

Figure 4 is a top plan view of the bearing element of i l 'Figure 2; f

Figure 5 is a top plan view of a guide channel with a bearing element positioned therein, corresponding generally to Figure l;` Y". yj

Figure 6 is a transverse vertical section taken substantially along line 6 6 of Figure 5 and showing a portion of a slidable sash mounted in the channel; and' Figures 7 and 8 are schematic plan views` illustrating the manner in which the weatherstripping pile fabric affords frictional resistance to a guide rib positioned therein conventional arrangements.

Having reference now to the drawings, whereinl like reference numbers designate the same part in each of the views, 10 indicates a conventional channel member which is adapted to receive a tongue or rib to guide a sash panel during movement. In window assemblies used on commercial passenger carrying vehicles, the channel member 10 may be a part of the metal window frame and the rib a part of the movable sash, or vice versa. As shown for the purpose of illustration in Figure 6, the rib 11 forms an integral part of a continuous metal sash frame 12 which encircles a sheet of laminated plate glass 14, the latter being mounted in glazing rubber 15 carried by the frame. The channel 10 with which rib 11 coacts, therefore, represents the window frame or a portion of the window frame in which the sash is slidably mounted.

Because of the interchangeability of the channel and rib locations, and also because the sash could be mounted for vertical as well as the horizontal sliding( movement, it will simplify the explanation and understanding of the invention if the parts are described with reference to their positions in the drawings, the portion of the sash frame shown being considered as the lower rail of a horizontally slidable sash. Thus, it will be understood that the terms top and bottom, etc. are used for convenience of explanation only and not in a limiting sense in either the specification or claims.

As will be apparent from Figure 6, there is no attempt to secure a close metal to metal t between the channel 10 and rib 11, and the clearance space therebetween is occupied by the weatherstripping material previously referred to. This weatherstripping material is a fabric having a heavy nap or pile 17, which fabric is generally called Schlegel cloth in the trade. The Schlegel cloth is usually mounted on a suitable metal support which forms with the cloth the weatherstripping unit, the support 18 in the present instance being of channel formation and of such width that it will have a friction tight fit in the guide channel 10. With this arrangement, the pile fabric covers the bottom and sides of the guide channel as is best shown in Figure l.

It was pointed out in the foregoing paragraphs that if the pile 17 of the weatherstripping occupies all of the clearance space between the guide channel and rib and is sufiiciently dense to provide a good seal, the sash will be diicult to move since the pile offers considerable frictional resistance to the movement and tends to bind the sash. This is schematically illustrated in Figures 7 and 8 which show in a somewhat exaggerated manner what happens to the pile when the sash, which is represented by a portion of its guide rib 11, is moved. Thus, when the sash is moved to the right as indicated by the arrow in Figure 7, the pile 17 is also pulled or bent towards the right due to the frictional engagement thereof with the metal rib. Thereafter, when the sash is moved to the left, Figure 8, the pile will be pulled in the opposite direction and the necessity for this direction change results in high starting friction whenever the sash is moved from the stationary condition.

In accordance with the present invention, the binding caused by both the starting friction and sliding friction is reduced to a minimum by mounting a plurality of antifriction bearing elements 20 at predetermined intervals in the guide channel weatherstripping as is best shown in Figures 1 and 5. These elements are preferably of unitary construction and are formed of a suitable smooth surfaced, wear resistant flexible material, nylon having proved to be the most satisfactory in actual practice. Each element 2,0 comprises a bottom portion 21 and a pair of side portions 22 extending upwardly from the bottom portion whereby the elements are substantially channel shaped in cross section. The side portions 22 are flared outwardly as at 24 adjacent the ends of the bearing elements and are tapered so that the end edges 25 thereof are substantially knife-edged. Similarly, the bottom portion 21 of each element is tapered at its ends so that it terminates in horizontal knife edges 27.

Intermediate its flared ends, each bearing element side portion 22 is formed with a plurality of outwardly extending, vertically disposedA Webs or ribs 2S, and these ribs and the knife edges 25, 27 project into the weatherstripping pile 17 when the bearing elements are positioned in the guide channels, and thus constitute a self-contained means for anchoring or holding the bearing elements in fixed position in the channels. The flared ends and knife edges also insure against the possibility of the bearing elements catching on the guide ribs 11. As best shown in Figure 3, the side portions 22 of the bearing elements are also formed so that they diverge slightly from the vertical or, in other words, are outwardly inclined. This small amount of outward inclination, which is approximately 3 in the embodiment shown, is very important since it allows the bearing elements to compensate for minor variations in the other components of the assembly and also ensures that the action of the self-contained holding means will be positive. Thus, when the bearing elements are inserted in a guide channel 10, the side portions of the elements are forced into a substantially vertical position by the pile fabric which brings them into Contact with the sides of the rib 11, Figure 6, but at the same time causes them to have an outward bias that increases the holding power of the knife edges 25 and ribs 28. In this connection, it will be noted that the presence of the bearing elements results in a partial displacement of the adjacent pile which becomes somewhat bent and matted as indicated at 30.

As is best shown in Figure 5, the weatherstripping pile 17 projects inwardly a short distance beyond the interior walls of the bearing elements 20 so that it will make good contact with the guide rib 11 and provide a truly Weather tight seal. Binding on the sash, however, is reduced to a minimum and easy movement thereof is ensured due to the spaced channel shaped bearing elements, the smooth interiors of which engage not only the bottom of the rib but the sides as well. In addition, the bearing elements serve to properly center the sash rib in the guide channel so that there is no uneven wear on the weatherstripping, and lateral play and cocking.

are prevented. The bearing elements can be positioned in the weatherstripped channels by simply pushing them downwaldly into position with a simple wooden tool similar lto a blunt edged putty knife, and when the elements are inserted so that the bottoms 21 thereof are down against the weatherstripping on the bottom of the channel, the top edges of the elements are substantially ilush with the channel top so that they are not visible or accessible for tampering.

As will be apparent to those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiment disclosed is therefore to be considered in all respects as illustrative rather than restrictive, the scope of the invention being indicated by the appended claims.

What is claimed is:

l. In a window assembly including a metal Window frame and a sash assembly movably mounted in said Window frame, said sash assembly including a glass panel and a metal sash frame encircling said panel, said window frame and sash frame having coacting guide channels and ribs to guide said sash assembly during movement, said window assembly also including separate weatherstrip channels positioned in said guide channels adapted to receive .Said guide ribs, said Weatherstrip channels having weatherstripping pile fabric on the bottom and side walls thereof engageable with said metal guide ribs; anti-friction structure to facilitate relative movement between said weatherstripping pile and metal ribs comprising a plurality of non-metallic channel shaped bearing elements positioned longitudinally in said weatherstrip channels at predetermined intervals therealong to slidably engage said guide ribs and provide anti-friction bearing surfaces therefor, said elements being mounted in said weatherstrip channels with the bottoms and sides thereof respectively engaging the pile fabric on the bottom and sides of the channels, the sides of said bearing elements being inclined outwardly as formed and being forced inwardly into contact with the sides of said guide ribs by the pile fabric on the sides of said weatherstrip channels, and means projecting outwardly from each of said bearing elements into said pile fabric, said projecting means coacting with the outward bias of said bearing element sides against the pile fabric to prevent relative movement between the elements and weatherstrip channels.

2. Anti-friction structure as defined in claim l wherein said projecting means comprise a plurality of vertically disposed holding ribs on the sides of each bearing element.

3. In a window assembly including a metal window frame and a sash assembly movably mounted in said window frame, said sash assembly including a glass panel and a metal sash frame encircling said panel, said window frame and sash frame having coacting guide channels and ribs to guide said sash assembly during movement, said window assembly also including weatherstripping pile fabric on the bottom and side falls of said guide channels for engagement with the metal guide ribs received therein;v

anti-friction structure to facilitate relative movement between said weatherstripping pile and metal guide ribs comprising a plurality of non-metallic bearing elements positioned at predetermined intervals in said guide channels to slidably engage the bottom and sides of said guide ribs and provide anti-friction bearing surfaces therefor, each of said bearing elements having a bottom portion and a pair of side portions extending upwardly from said bottom portion whereby said elements are substantially channel shaped in cross section, said elements being mounted longitudinally in said guide channels with the bottoms and side portions thereof respectively engaging the pile fabric on the bottom and sides of the channels, the side portions of each of said elements bein-g outwardly flared at the ends of the elements, and means projecting outwardly from said side portions intermediate the ends thereof, said outwardly ared ends of the elements and outwardly projecting means being embedded in the pile fabric on the sides of said guide channels to prevent relative movement between the elements and channels.

4. In a window assembly including a metal window frame and a sash assembly movably mounted in said Window frame, said sash assembly including a glass panel and a metal sash frame encircling said panel, said window frame and sash frame being formed with coacting guide structure including interengaging channels and ribs to guide said sash assembly during movement, said window assembly also including weatherstripping pile fabric in the inside of said guide channels on the bottom and side walls thereof to engage the portion of said metal guide ribs received within the channels; anti-friction structure to facilitate relative movement between said weatherstripping pile and the metal guide ribs in engagement therewith comprising a plurality of non-metallic bearing elements positioned at predetermined points along the length of said guide channels to slidably engage the bottom and sides of said guide ribs and provide anti-friction bearing surfaces therefor, each of said bearing elements having a bottom portion and a pair of side portions extending upwardly from said bottom portion whereby said elements are substantially channel shaped in cross section, said elements being mounted longitudinally in said guide channels with the bottom and side portions thereof respectively engaging the pile fabric on the bottom and sides of the channels, said upwardly extending element side portions being formed with a slight outward inclination and being forced inwardly into contact with the sides of said guide ribs by the pile fabric on the sides of said guide channels, the side portions of said elements also being flared outwardly at the ends of the elements, and a plurality of vertically disposed holding ribs projecting outwardly from the side portions of each of said elements intermediate the ends thereof, said outwardly ared ends of the elements and outwardly projecting holding ribs coacting with the outward bias of said element side portions against the pile fabric to prevent relative movement between the elements and guide channels.

5. Anti-friction structure as defined in claim 4 wherein the pile fabric on opposite sides of said guide channels projects inwardly to define a narrow guide rib receiving channel therebetween, the width of said narrow channel being less than the interior width of said bearing elements to ensure weather tight contact between the pile fabric and guide ribs at every point along said guide channels except where said bearing elements are positioned.

6. In a window assembly including interengaging metal guide channels and guide ribs, said guide channels having weatherstripping pile fabric on the bottom and side walls thereof for engagement with the guide ribs received therein; anti-friction structure to facilitate relative movement between said weatherstripping pile and the metal guide ribs in engagement therewith comprising a plurality of relatively short non-metallic channel shaped bearing elements positioned at predetermined points along the length of said guide channels to slidably engage the bottom and sides of said guide ribs and provide anti-friction bearing surfaces therefor, said elements being mounted longitudinally in said guide channels with the bottom and sides thereof respectively engaging the pile fabric on the bottom and side walls of the channels, the sides of said bearing elements being formed with a slight outward inclination and being forced inwardly into contact with the sides of said guide ribs by the pile fabric on the side walls of said guide channels, the sides of said elements also being ared outwardly at the ends of the elements, and a plurality of vertically disposed holding ribs projecting outwardly from the sides of said elements intermediate the ends thereof, said outwardly ared ends of the elements and outwardly projecting holding ribs coacting with the otuward bias of the sides of the elements against the pile fabric to prevent relative movement between the elements and guide channels', the outwardly ared ends of each of said bearing elements and the ends of the bottom thereof being knife edged to further insure against relative movement between the elements and guide channels and also to prevent the elements from catching on said guide ribs.

References Cited in the le of this patent UNITED STATES PATENTS 2,759,773 Wilmer et al Aug. 2l, 1956 2,790,214 Edwards, Sr. et al Apr. 30, 1957 2,796,960 Reynolds June 25, 1957 FOREIGN PATENTS 561,149 Germany Oct. 11, 1932 386,504 Great Britain Jan. 19, 1933 

